1. Field of the invention
The present invention is concerned with an automatic stop mechanism for an electronic tape apparatus and a centrifugal clutch mechanism for effectively operating the stop mechanism when the voltage of an electric source is lowered.
2. Description of the prior art
According to the prior art, such automatic stop mechanism generally comprises a sensing means for detecting when a tape is stopped and an unlocking means for unlocking a mechanism blocking the running condition of the tape. Nowadays, there are many kinds of the sensing means or system for example,
A. A tape tension system using tape tension developed in a tape running between reels when it is stopped. The strained condition of the tape is detected by a detector placed along the tape's passage and pressed by the tape.
B. A sensor system using a photoelectric sensing means or a physical sensing device in order to detect or place a marking formed on an end of a tape.
C. A rotational difference system using a rotating wheel contacting a reel. When the reel is stopped, an unlocking lever having a roller is drawn into a place between the stopped reel and the rotating wheel owing to the rotational difference between them.
They have specific shortcomings and the present invention seeks to resolve these shortcomings of the prior art.